Container body and method of making the same



llnited States Patent [72] Inventors Stephen F..Iensen Bronx County;Willard A. Meyer, South Salem, New York [21] Appl. No. 764,273 [22]Filed Oct. 1, 1968 [45] Patented Nov. 17, 1970 [73] Assignee AmericanCan Company New York, New York a corporation of New Jersey [54]CONTAINER BODY AND METHOD OF MAKING THE SAME 8 Claims, 7 Drawing Figst[52] US. Cl 138/150, 138/144, 138/154; 220/65, 220/75 [51] 'Int. Cl F1619/16 [50] Field of Search 138/144,

135, 136, 150, 154; 220/65, 75, 83, 63(cur) [56] References Cited UNITEDSTATES PATENTS 3,338,270 8/1967 Denenberg Primary Examiner-Herbert F.Ross Attorneys-Robert P. Auber, George P. Ziehmer, Kenneth H. Murray andJohn E. Wilson ABSTRACT: A tubular, spirally wound multiply containerbody includes a body ply of fibre stock which has a liquidproot barrierlayer prelaminated or otherwise preafiixed to one surface thereof.Material on the reverse side of both marginal edge portions of theresultant laminated ply is removed by av skiving operation, therebyreducing the thickness of the marginal edge portions. One of thethinned, skived, marginal edge portions is folded back on itself, andthis folded edge portion is then helically wound in lapping relationshipto the unfolded edge portion and bonded to it to form a sealed helicallap seam having a thickness substantially equal to that of the unskivedportions of the ply.

CONTAINER IIODY AND METHOD OF MAKING THE SAME BACKGROUND OF THEINVENTION Spiral can-manufacturing techniques have resulted in theproduction of spirally wound container bodies wherein at least twostrong, rigid fibre bodyplies are sandwiched between an such thinbarrier materials to the handling required in the spiralcan-manufacturing process, they have heretofore been prelaminated to asuitable strong backing layer (e.g. thin kraft paper) and .the resultinglaminations fed to the wider as separate plies which are independent ofthe main body plies and require their own handling and feedingequipment.

The present invention provides a container construction wherein thebacking layer is eliminated and the barrier layer is integrated with amain body ply by being prelaminated, precoated, or otherwise preapplieddirectly to the main body ply prior to time the latter is wound onto theforming mandrel. Thus, by way of example, a thin layer of a plasticmaterial such as polyethylene is extruded directly onto a main body plyand the resultant integrated barrier bearing body ply is substituted forthe separate body and barrier plies heretofore used. This integrated plyconstruction is best adapted to provide the inner liner for the body,but it can, under some circumstances also be adapted to provide anexternal moistureproof body layer.

The physical nature of the barrier will be determined by therequirements of the finished container. Thus, the barrier can be aplastic such as polyethylene which is extruded directly onto a body ply,or can be thin aluminum foil which is adhesively secured to the bodyply. If it is desired to also have the barrier function as a label, itmay comprise thin, preprinted aluminum foil or thin preprinted varnishedpaper which is prelaminated to the outer body ply by means of a suitableadhesive.

In order to prevent leakage of fluids or moisture into the fibre bodyplies in the area of themarginal edge portions of the helically woundplies, and particularly 'at the ends of the body where these edgeportions extend into the end seams, each prelaminated ply is treated insuch manner as to form these edge portions into a sealed overlappedjoint of a thickness substantially the same as the thickness of theother. adjacent portions of the ply. To this end, both marginal edgeportions of the ply, on the surface opposite to that which carries thebarrier layer, are skived or milled away, and one ofthe skived edgeportions is folded back on itself, and then lapped over and sealed tothe opposite skived edge portion, thus forming a single thickness lappedhelical seam which winds smoothly onto the winding mandrel withoutabrasion of its surfaces and minimizes or eliminates the formation ofprojecting stepped portions in the helical seam which might provide openchannels to permit the flow of the product into the end joints ofthecontainer, and thence into the main body plies.

Thus, it can be seen that a main object of this invention is toreducethe number of separate plies of stock which must be fed onto thewinding mandrel of a spiral winder in order to produce a strong,leakproof, spirally wound container body,

and that other advantageous results such as operating andmaterialeconomies, and a better, more integrated body construction, are alsoachieved.

SUMMARY OF THE INVENTION In making a tubular container body, a main bodyply offibre material having a barrier prelaminated or otherwisepreaffixed on one surface thereofis helically wound on a mandrel. As theintegrated prelaminated body ply is fed to the winding mandrel, edgeportions of its opposite unprotected surface are removed by skiving,thereby to form marginal edge portions of reduced thickness.Subsequently, one of said'marginal edge portions is folded back onitself with said barrier'dispose'd externallyof the fold, and the ply ishelically wound on a mandrel in such manner that the folded-back portionis lapped over and indented into the unfolded skived oppositeedgdportion, and bonded thereto. as by fusion to form a leakproof,single thickness helical lap joint.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view ofanapparatus capable of performing the method steps of the instantinvention;

FIG. 2 is'a perspective view ofa sealed composite container having aspirally wound body formed according to the present invention; I

FIG. 3 is a fragmentary sectional detail taken substantially along theline 3-3 of FIG. 1 and showing the integrated. prelaminated inner bodyply skived on opposed marginal edge portions;

FIG. 4 is a fragmentary'sectional detail taken substantially,

along the line 4-4 of FIG. 1 and showing one of the marginal edgeportions of the integrated ply folded back on itself;

FIG. 5 is a sectionaldetail taken substantially along line 5-5 of FIG. Iand showing the helical seam formed after the folded back edge portionof the integrated ply has been lapped over and embedded into theunfolded opposite skived edge portion ofthe ply during the spiralwinding operation;

FIG. 6 is an enlarged sectional view taken substantially along the line6-6 in FIG. 2; and

FIG. 7 is a sectional view similar to FIG. 6, but on a reduced scale,showing a modified form of the invention.

BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS As a preferred andexemplary embodiment of the instant invention. FIG. 2 shows a compositecontainer I0 which is formed with a cylindrical. spirally wound body l2having its opposite ends closed by top and bottom imperforate metal endclosure members I4 and 16, respectively, which are suitably securedthereto in fluid-tight end seams 18 which may be of. any suitable type.The body 12 is formed bywinding various plies helically. around astationary mandrel 28of a spiral winder (see FIG. 1) to form themcontinuously into a tubefl" which is subsequently cut into bodies 12 bycutting knives (not shown) in the usual manner. One end of the mandrel28 is fix edly mounted in a mounting block 30, the other end ofthemandrel 28 being free in order that the tube T may be dischargedtherefrom.

As seen in FIG. 6, the body 12 is formed by a suitable exterior labelply 20 (rag. printed aluminum foil mounted on a paper backing), heavyouter and inner main body fibre (2.3. kraft or chipboard) plies 22 and24. respectively, and-u liquidpro'of liner barrier 26, here shown as athin layer of extruded polyethylene. In the several drawings, therelative thickness of the various pliesand layers are greatlyexaggerated for the sake of clarity of illustration.

The barrier .26 and the inner main body ply 24 are laminated to eachother prior to thetime they are wound on the'mandrel 28, preferablybefore these plies are fed toward the mandrel 28, although it ispossible to do this while they are being fed toward the mandrel 28.Prelaminating or preaffixing of the two materials 24 and 26 to oneanother is intended to onto the body ply 24, the spraying of a barrierlayer onto the body ply 24 or, if the barrier layer be a preformed layersuch as thin aluminum foil, the laminatingof it to the body ply- 24 witha suitable adhesive.

The prelaminated integrated inner fibre body ply 24'is fed toward themandrel 28 at the proper winding angle from a suitable supplyroll (notshown) carried on an unwind stand (not shown). As the prelaminated ply24 is fed toward the mandrel 28, the marginal side portions thereof, theside edges of which are initially squared or normal to the top andbottom surfaces of the ply, are skived by a pair of rotating abrading ormilling knives 32 and 33, respectively. The knives 32, 33 are rotated athigh speeds to remove portions of the fibre body to form the contourssubstantially as shown in FlG. 3. The knife 32 operates to remove stockfrom the forward marginal edge portion (to the right as seen in FIG. I)of the upper surface of the ply 24, to produce thereon a bevel portion34 having a gently sloping skived surface 35 while the knife 33 producesin the rearward marginal edge portion a right angled step 36 which isdefined by a flat skived surface 37, which is parallel to the barrierlayer 26 which remains undisturbed on the reverse side of the ply 24,and a short vertical skived wall 38.

Thereafter, the skived body ply 24 passes below an adhesive applicator40 which deposits a suitable adhesive 41, which may be water or solventbased or of the hot melt type, in the form of a continuous bead or filmon the flat skived surface 37 of the stepped marginal edge portion 36.Subsequently, the body ply 24 is passed through a plow 42 having a camsurface formed thereon which folds the outer portion 43 of the steppedmarginal edge portion 36 backwardly over the inner portion thereof toform a fold or hem 44 (as shown in FIG. 4), the bead or film of adhesive41 being spread out within the fold 44 as the latter is formed.

The fold 44 then passes between a pressure roller 46 and a suitableunderlying support (e.g. another roller, not shown) which cooperate topress the fold 44 with the adhesive 41 therebetween to form it into asolid, adhesivcly seamed structure. If desired, a water or solvent basedadhesive 41 may be selected which will penetrate and impregnate thefibre portions of the fold 44 and thus provide an auxiliary barrier tothe leakage of liquid into the body ply 24 in the event that a crack ortear should inadvertently occur in the barrier layer 26 of the hem 44during the folding operation.

The laminated fibre body ply 24, formed as heretofore described, is thenwound onto the mandrel 28 with the liner barrier 26 contacting themandrel 28. As the ply 24 is wound on the mandrel 28, its beveledmarginal edge portion 34 is laid onto the hem 44. Under the pressure ofthe winding, the beveled portion 34 is reshaped, as it is wound onto thehem 44 of the folded marginal edge portion 35, to the configurationshown in FIG. 5, so that in effect, the hem 44 is indented into thebevel portion 34 and forms a single thickness lap seam S which forms asmooth nonprojecting portion of the wound ply More specifically, in theprocess of contacting the fold 44, which is supported directly on themandrel 28, the marginal edge portion 34 is offset outwardly radiallyfrom the center line of the mandrel 28. In being thus forced outradially, the beveled marginal edge portion 34 is reshaped substantiallyfrom a contour of FIG. 4 wherein its skived surface 35 forms a slopingextension of the surface of the adjacent unskived central portion of thebody ply 24, to the contour of FIG. wherein it forms a substantiallystraight extension thereof. These reformed areas will not, of course, bei completely smooth, but any surface irregularities therein will tend tobe ironed out as the formation of the tube T progresses.

lt will be noted that the mutually contacting surfaces of the marginaledge portions of the ply 24 within the seam S comprise portions of thebarrier layer 26. In order to seal the seam S and prevent leakage ofproduct through it and into the interior of the ply 24,these mutuallycontacting barrier surfaces are heated by suitable heaters, as bydirectional, controlled gas flames 47, 48, in order to soften theplastic barrier material 26 and cause it to fuse together in theinterior ofthe seam S (as shown by the small 5 in the drawings) and thusbond the lapped marginal edge portions together.

If the barrier 26 is not a thermoplastic material, a separate adhesivecan be applied to the fold surface 43, as the ply 24 approaches themandrel 28, in order to obtain an adhesive bond in the seam S. t

As will be apparent in FIG. 5, the thickness of the helical seam S issubstantially that of the laminated body ply 24. In this regard, it isnoted that it is undesirable to have a helical seam which issubstantially thicker than the body ply 24 because there would be atendency for leak channels to occur where the thicker helical seamportions are incorporated in the end seams 18 which affix the ends l4,16 to the container body 12, thus facilitating passage of the productinto the end seams 18. In addition, if the seam S were thicker than thebody ply, its inside surface would be subject to abrasion as it movedalong the mandrel 28 because of the concentration of pressure in suchthicker areas.

According to the present invention, the total thickness of the helicalseam S is controlled to obtain the desired seam thickness by controllingthe depths to which the fibre material is skived from the marginal edgeportions 34, 36.

After the laminated body ply 24 has been wound onto the mandrel 28, theouter main body ply 22 is wound on top ofit. The ply 22 is fed from asuitable supply roll (not shown) and approaches the mandrel 28 from theside opposite to that from which the laminated body ply 24 approachesit. The inner surface of the body ply 22 is coated with a film ofadhesive 52 by an applying roller 54 to cause it to adhere to the outersurface of the ply 24, and its edges may be butted together as indicatedby the numeral 56 or joined in any other suitable manner, as by theskived joint disclosed in US. Pat. No. 3,280,709.

The partially formed tube structure is then passed through a windingbelt 64 which is wrapped around the mandrel 28. The belt 64 is mountedon a driving drum 66 and an idle drum 68 and functions to compress thewound plies and to rotate and advance the partially formed tubelongitudinally along the mandrel 28 and to pull the various tube pliesfrom the supply rolls. The pressure of the winding belt helps to smoothout any irregularities in the surfaces ofthe seam S.

After the partially formed tube structure emerges from the belt 64, thelabelply 20 is fed onto it at the winding angle and wrapped around it toform the completed tube T. Prior to reaching the mandrel 28, the labelply 20 has an overall film of an adhesive (not shown) applied to itsinner surface by an applying roll 70. Although the label ply 20 is shownin the drawings as consisting of a single layer, it may and usually doesconsist ofthinfoil (e.g. aluminum) prelaminated to a supporting paperbacking layer. The label ply 20 preferably is preprinted with suitableunitary label designs L (see FIG. 1) and is of su fficient width toprovide an overlapped helical joint 72 (FIG. 6).

After completion of the tube T, it is cut into suitable lengths anddischarged in any suitable manner over the free end of the mandrel 28.The cutting of the tube T in registration with the label patterns L maybe done in accordance with the method described in B. Robinson US. Pat.No. 2,737,09l, granted Mar. 6, I956.

FIG. 7 illustrates a container construction wherein the principles ofthe instant invention are applied to the outer body ply 22, as well asto the inner ply 24. In this construction, the ex ternal barrier 20',which may be a suitable material such as an extruded plastic or anadhesively secured paper, metal foil or plastic film (which materialsmay or may not carry a label pat tern L) is preapplied to the body ply22 in the same manner as the inner barrier 26 is preapplied to the innerbody ply 24. The resultant integrated, prelaminated ply has its opposingedges skived, folded, overlapped, and bonded together to form anexternal, sealed, helical seam E which is substantially similar to theinternal seam S, to thereby provide a body which is completelyimpervious to both internal and external fluids and moisture. Ifdesired, an additional body ply (or plies) may be interposed between theplies 22,24 to provide an even stronger heavier, body construction. Theseams E and S are preferably offset from each other a suitable distance(preferably one-half the pitch of the tube) to insure a strong, solidtube structure.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description and it will beapparent that various changes may be made in the form, construction, andarrangement of the parts and that changes may be made in the steps ofthe method described and their order of accomplishment without departingfrom the spirit and scope of the invention or sacrificing all of itsmaterial advantages, the form hereinbefore described being merely apreferred embodiment thereof.

We claim:

1. A multiply tubular container body including a helically woundcomposite ply comprising a layer of fibre stock having a barrierpreaffixed on one surface thereof, said ply having opposed marginalskiving the reverse surface of the ply, one of said skived marginal edgeportions being folded backwardly on itself to form a marginal edge foldwith said barrier disposedoutwardly of the fold said helically woundfibre ply having its opposed marginal edge portions arranged inoverlapping relationship with said fold being in facing relationshipwith the barrier on the opposite marginal edge portion and beingindented into said marginal edge portion to offset said oppositemarginal edge portion and to form therewith a helical seam ofa thicknessapedge portions of reduced thickness formed by proximately the unskivedthickness of said ply, themutually contacting surfaces of the barrierwithin suidhclical seam being fused together to form a leakproof sealtherein.

2. A tubular container body according to claim 1 wherein said helicalscam does not project beyond the normal contour of said helically woundply.

3. A tubular container body according to claim I wherein the marginaledge portion to be folded is formed with a right angled skive.

4. A tubular container body according to claim 3 wherein the oppositemarginal edge portion is formed with a beveled skive. v

5. A tubular container body according to claim 4 wherein the mutuallyfacing f bre surfaces within said fold are adhesively bonded together.

6. A tubular container body according to claim 5 wherein the fibre stockwithin said fold is impregnated with a leak-rcsistant material' 7. Atubular container body according to claim 1 wherein said composite plycomprises the innermost ply of said body.

8. A tubular container body according to claim l wherein said compositeply comprises the outermost ply ofsaid body.

